Experimental and theoretical studies on oxidation of Cu-Au alloy surfaces; Effect of bulk Au concentration

Okada, Michio*; Tsuda, Yasutaka*; Oka, Kohei*; Kojima, Kazuki*; Dio, W. A.*; Yoshigoe, Akitaka; Kasai, Hideaki*

Scientific Reports (Internet), 6, p.31101_1 - 31101_8, 2016/08

https://doi.org/10.1038/srep31101

We report results of our experimental and theoretical studies on the oxidation of Cu-Au alloy surfaces, viz., CuAu(111), CuAu(111), and AuCu(111), using hyperthermal O molecular beam (HOMB). We observed strong Au segregation to the top layer of the corresponding clean (111) surfaces. This forms a protective layer that hinders further oxidation into the bulk. The higher the concentration of Au in the protective layer formed, the higher the protective efficacy. As a result, of the three Cu-Au surfaces studied, AuCu(111) is the most stable against dissociative adsorption of O, even with HOMB. We also found that this protective property breaks down for oxidations occurring at temperatures above 300 K.

In situ XAFS and HAXPES analysis and theoretical study of cobalt polypyrrole incorporated on carbon (CoPPyC) oxygen reduction reaction catalysts for anion-exchange membrane fuel cells

Asazawa, Koichiro*; Kishi, Hirofumi*; Tanaka, Hirohisa*; Matsumura, Daiju; Tamura, Kazuhisa; Nishihata, Yasuo; Saputro, A. G.*; Nakanishi, Hiroshi*; Kasai, Hideaki*; Artyushkova, K.*; et al.

Journal of Physical Chemistry C, 118(44), p.25480 - 25486, 2014/11

https://doi.org/10.1021/jp507534f

Design concept of the precious-metal-free automotive catalyst using copper oxide and alloys

Nishihata, Yasuo; Tanaka, Hirohisa*; Mitachi, Senshu*; Kasai, Hideaki*

Kogyo Zairyo, 62(5), p.41 - 44, 2014/05

no abstracts in English

Evaluation of the applicability of a new quantitative rock mass classification method at the Mizunami Underground Research Laboratory

Kuji, Masayoshi*; Asai, Hideaki*; Hashizume, Shigeru; Horiuchi, Yasuharu; Sato, Toshinori; Matsui, Hiroya

JAEA-Technology 2013-022, 72 Pages, 2013/10

JAEA-Technology-2013-022.pdf:5.3MB

Rock mass classifications are used for design and construction of underground structures. However, the classification methods commonly used in Japan are qualitative and inadequate for estimating the actual mechanical properties of a rock mass based on site specific geological features. Considering the design, construction and safe operation of large underground facilities, an important requirement is to utilize a rock mass classification method that can estimate site specific rock mechanical properties based on surface-based investigations and geological observations during excavation. For this study, a new quantitative rock mass classification method based on JGS standard was proposed and applied to the sedimentary formations and the granite at MIU. The results were compared with the rock mass classification system developed by CRIEPI and commonly used in JAPAN. Then the applicability of the new rock mass classification could be evaluated.

A Theoretical study of the reactivity of CuO(111) surfaces; The Case of NO dissociation

Kishi, Hirofumi*; Padama, A. A. B.*; Arevalo, R. L.*; Moreno, J. L. V.*; Kasai, Hideaki*; Taniguchi, Masashi*; Uenishi, Mari*; Tanaka, Hirohisa*; Nishihata, Yasuo

Journal of Physics; Condensed Matter, 24(26), p.262001_1 - 262001_5, 2012/07

https://doi.org/10.1088/0953-8984/24/26/262001

no abstracts in English

Examination concerning application of ACROSS to engineering technology of the MIU project; Annual report, fiscal year 2009

Hasegawa, Ken; Kunitomo, Takahiro; Nakajima, Takahiro*; Asai, Hideaki*; Iyatomi, Yosuke; Matsui, Hiroya

JAEA-Evaluation 2011-001, 150 Pages, 2011/06

JAEA-Evaluation-2011-001.pdf:28.92MB

ACROSS has developed to acquire the detailed information on the tectonically active zone. The technology for example the transmission and receiving technique, the data analysis and the interpretation technique of the ACROSS signal is able to apply not only to seismology but also to other field. We considered the ACROSS technology may apply to the engineering technology of the MIU project, for example monitoring of the change of the geological environment around shafts and also the strength of the shaft concrete itself. It is planned that the examination for three years will be made from fiscal year 2007. The first year is expansion of the network of observation stations, the second year is data acquisition and last year is the analysis of data and evaluation of the ACROSS. In this report, we describe the results of fundamental studies of the ACROSS and the processing results obtained from the ACROSS observation stations which were prepared in fiscal year 2007 and 2008, also describe the current evaluation results of the ACROSS.

Proceedings of ACROSS Workshop on "Current state of ACROSS technology and view in the future"

Asai, Hideaki; Hasegawa, Ken

JAEA-Review 2010-050, 222 Pages, 2010/11

JAEA-Review-2010-050.pdf:25.5MB

ACROSS (Accurately Controlled Routinely Operated Signal System) has developed to acquire the detailed information on the tectonically active zone. We considered the ACROSS technology may apply to the engineering technology of the MIU project, for example monitoring of the change of the geological environment around shafts and also the strength of the shaft concrete itself. It was planned that the examination for three years will be made from fiscal year 2007. We held ACROSS Workshop "Current state of ACROSS technology and view in the future" on February 24 and 25, 2010 at Mizunami. The purpose of the ACROSS Workshop was to introduce our current result of the ACROSS research, to introduce the research of the ACROSS technology to external specialists, and to discuss the view of the ACROSS technology in the future. This report is collection of the documents used in the ACROSS Workshop.

Applicability for the estimation of a rock strength by Schmidt hammer based on in-situ measurement

Kuji, Masayoshi*; Asai, Hideaki; Matsui, Hiroya

Doboku Gakkai Heisei-22-Nendo Zenkoku Taikai Dai-65-Kai Nenji Gakujutsu Koenkai Koen Gaiyoshu (DVD-ROM), p.139 - 140, 2010/09

Two deep shafts (the Main Shaft and the Ventilation Shaft) at The Mizunami Underground Research Laboratory (MIU) is currently being constructed by Japan Atomic Energy Agency (JAEA). To estimate the rock mass quality and UCS on shaft wall, existent rock mass classification methods (CRIEPI, RMR and New-JH) and in-situ Schmidt hammer tests were applied in rock. In this report, applicability for the estimation of rock strength by Schmidt hammer is discussed based on in-situ measurement data.

Examination concerning application of ACROSS to engineering technology of the MIU project; Annual report, fiscal year 2008

Hasegawa, Ken; Kunitomo, Takahiro; Nakajima, Takahiro; Asai, Hideaki; Iyatomi, Yosuke; Matsui, Hiroya

JAEA-Evaluation 2009-006, 120 Pages, 2010/01

JAEA-Evaluation-2009-006.pdf:32.94MB

ACROSS (Accurately Controlled Routinely Operated Signal System) has developed to acquire the detailed information on the tectonically active zone. The technology for example the transmission and receiving technique, the data analysis and the interpretation technique of the ACROSS signal, is able to apply not only to seismology but also to other field. We considered the ACROSS technology may apply to the engineering technology of the MIU project, for example monitoring of the change of the geological environment around shafts and also the strength of the shaft concrete itself. It is planned that the examination for three years will be made from fiscal year 2007. The first year is expansion of the network of observation stations, the second year is data acquisition and last year is the analysis of data and evaluation of the ACROSS. In this report, we describe the results of fundamental studies of the ACROSS and the preliminary processing results obtained from the ACROSS observation stations which were prepared in fiscal year 2007 and 2008.

Countermeasures planned for reducing water inflow into deep shafts at the Mizunami Underground Research Laboratory (Research for post-excavation grouting)

Kuji, Masayoshi*; Matsui, Hiroya; Hara, Masato; Minamide, Masashi*; Mikake, Shinichiro; Takeuchi, Shinji; Sato, Toshinori*; Asai, Hideaki

JAEA-Research 2008-095, 54 Pages, 2009/01

JAEA-Research-2008-095.pdf:13.14MB

A large amount of water inflow is frequently generated during the excavation of an underground cavern, such as road and railway tunnels, underground electric facilities etc. The reduction of water inflow is sometimes quite important for the reduction of cost for the water treatment and pumping during the construction of an underground cavern. The Mizunami Underground Research Laboratory (MIU) is currently being constructed by Japan Atomic Energy Agency. During its excavation, a large amount of water inflow into the shafts has been increasing and affecting the project progress. Therefore, a field experiment of post-excavation grouting around the Ventilation Shaft in a sedimentary formation carried out to confirm the effect of existing grouting technology for sedimentary formations in MIU project. The result shows that the applied methods in this field experiment are effective to prevent water inflow. This report describes the summary of the field experiment and the knowledge obtained through the experiment.